I just think it's becoming more and more clear it is now a PG driven league (just look at the final 4 teams - 3 of the best PGs in the NBA in Rose, Westbrook, Kidd with James playing a hybrid Point forward role most of the time for the Heat). Add in how Chris Paul almost single handedly beat the Lakers, then how Barea and Kidd torched them via lighting up Fisher, how Rondo was the key to the Celtics and when he got hurt it ended their season, the Nets mortgaging their future for simply the chance to have Deron Williams (even if he does bolt after this year), Conley Jr. helping to lead the Griz to a suprising run in the playoffs, Jru Holliday helping to lead a suprising Sixers team to the playoffs, Lawson and Felton rejuvinating the Nuggets post-Melo, and Steve Nash singlehandedly keeping the Suns relevant.
I just think if you have the chance to get a franchise PG you can't pass it up, even if you think Williams might be a little better prospect right now. Ask the Hawks how they feel about taking Marvin Williams over CP3. Ask the Knicks how they feel about passing up on Lawson, Holliday, Jennings, Collison, or even Eric Maynor to pick Jordan Hill. Just my opinion, but if I'm the Cavs it's not even a debate who you take 1st. The 4th pick is a different story, but Irving is a great place to start.